Since collapsing in Game 2, the Boston Celtics have appeared invincible.

The Celtics defeated the Miami Heat for the third time in a row on Wednesday night at TD Garden, capping out their first-round playoff series. After nearly taking a 20-point lead after the first quarter, the Celtics cruised to a 118-84 victory in Game 5 of their series against the Heat.

That advanced Boston to the Eastern Conference playoffs for the seventh time in eight seasons.

The Celtics took off immediately Wednesday, effectively ending the game after the first 12 minutes. They made eight 3-pointers in the first period and went 14 of 21 from the field to take an 18-point advantage at the intermission. Derrick White scored 15 of his 25 points in the first quarter.

The Celtics opened the second quarter with a 14-2 run, highlighted by a massive Jaylen Brown 3-pointer, to grab a 30-point lead. Though the Heat improved slightly before halftime, they still behind by 22 points.

By then, the game had ended. The Celtics extended their lead to 30 points in the third quarter before holding on for a 34-point victory. The Celtics won all four games in this series by double digits, with an average margin of 22 points per game.

Bam Adebayo led the Heat with 23 points, all but two coming in the first half. In addition to his six assists, he added five rebounds. Tyler Herro scored 15 points but only made 1 of 8 from beyond the arc. Caleb Martin scored 10 points and was the only other Heat player to reach double figures.

Brown finished with 25 points and six rebounds, while White added six rebounds to his 25 points. Jayson Tatum tallied 16 points and 12 rebounds. They shot over 55% from the field as a team and outrebounded the Heat 56-29.

The Celtics are now the first Eastern Conference team to advance beyond the first round of the playoffs. They await the outcome of the Cleveland Cavaliers-Orlando Magic series. The Cavaliers have a 3-2 series advantage going into Friday’s Game 6.

Kristaps Porzingis is likely out till the conference finals.Though the Celtics have advanced to the next round, Kristaps Porzingis is not returning anytime soon.

According to TNT’s Chris Haynes, the Celtics center, who suffered a calf strain after making an unfortunate move in their Game 4 victory on Monday, isn’t expected to return until the Eastern Conference finals.

That means that, following their victory on Wednesday, the Celtics will need to beat either the Cavaliers or the Magic in the semifinals without him. Even yet, there is no assurance Porzingis will be available for the start of the conference finals.

Porzingis has averaged 20.1 points and 7.2 rebounds per game this season for the Celtics. He has averaged 12.3 points and five rebounds in their first-round playoff series, scoring 18 points in both of their victories in Games 1 and 3.